As the population continues to age, the incidence of dementia is dramatically increasing, resulting in an urgent need to identify risk factors for abnormal brain aging and dementia. Alterations in cardiac function influence systemic blood flow, which impacts cerebral blood flow homeostasis as demonstrated by animal models. Such changes in cerebral blood flow homeostasis may pose a risk for accelerating age-related brain injury. Our preliminary research suggests that cardiac function is related to markers of maladaptive brain aging. It is not yet clear if cardiac function accelerates neuroimaging or cognitive markers of cerebrovascular or Alzheimer's disease among aging individuals with mild cognitive impairment (MCI). Individuals with MCI are at increased risk for cognitive progression and susceptible to more rapid abnormal brain aging when concomitant vascular disease is present. Our proposed study will examine relations between cardiac function and maladaptive brain aging and provide important information for developing novel strategies to delay the progression from MCI to dementia. Using a prospective observational matched design, we will cross-sectionally and longitudinally relate cardiac function to neuroimaging and cognitive markers of early Alzheimer's disease and cerebrovascular changes among aging adults with MCI and age-, sex-, and race-matched cognitively normal adults. Clinical or subclinical cardiac dysfunction may be due to complex systemic mechanisms that are preventable or treatable, such as enhanced inflammatory markers and insulin resistance, or genetic factors, such as apolipoprotein E. Therefore, we will consider systemic and genetic factors as potential mediating mechanisms in relations between cardiac function and brain aging. The proposed study leverages an existing Alzheimer's Association funded study directed by the principal investigator, the participant registry of our NIA-funded Boston University Alzheimer's Disease Center, a recent American Recovery & Reinvestment Act supplement grant focused on African American recruitment and retention, and the unique resources afforded by our local Clinical and Translational Science Institute housing the General Clinical Research Unit.